共查询到20条相似文献，搜索用时 156 毫秒
1.
董金辉 《黄冈师范学院学报》2005,25(6):73-75
拟合法是一种常用且重要的数学方法，常数拟合法是将常数作适当的分解，在分析数学上解决很多问题，本文就如何利用常数拟合法解决一些特殊极限问题，作了一些探讨。 相似文献
2.
对曲线拟合中的正交多项式拟合法作了研究;介绍了正交多项式的概念,给出了正交多项式拟合法及相应的程序实现;本论文的研究,对从事计算科学的工作者在做数据拟合时具有指导意义 相似文献
3.
4.
GPS水准拟合方法比较 总被引：1，自引：0，他引：1
主要介绍GPS水准拟合中的多项式拟合法和Shepard曲面拟合法的基本原理。以我国某地区(52 km×100km)的实测高程异常数据和GPS/水准数据为例,对多项式拟合模型的选取和Shepard曲面拟合法中拟合参数的确定等进行了讨论。 相似文献
5.
郭辉 《河北职业技术学院学报》2014,(1):98-102
人力资源规划是高等学校人力资源管理专业基础课程中的重要内容之一。其中,利用统计学的定量方法对企业人力资源需求进行合理预测是人力资源规划的重点和难点。由于此部分内容涉及较多的统计学分析内容,在教学过程中师生普遍反映有一定的难度。究其原因,主要在于学生未能把统计学相关分析内容与人力资源需求预测的研究思路紧密地结合起来。鉴于此部分内容在研究方法上有一定的共性,在此,结合实际教学经验,归纳出趋势方程拟合法在人力资源需求预测的应用范式,以便于教学中应用。 相似文献
6.
用加权平均法拟合线性方程 总被引：2，自引：0，他引：2
傅在琦 《昭通师范高等专科学校学报》2006,28(5):23-25
当测量数据满足一定条件时，用加权平均法拟合的线性方程与用最小二乘法拟合的线性方程相同，这有效地解决用最小二乘法处理数据十分繁冗的问题． 相似文献
7.
MATLAB在光学实验中的应用 总被引：2，自引：0，他引：2
利用MATLAB强大便捷的科学计算功能，引入多项式拟合法处理牛顿环实验数据，提高了实验的测量精度，拓展了测量范围；基于MATLAB的科学可视化功能对光学实验现象进行计算机模拟，在实验教学中应用效果明显。 相似文献
8.
陈荣强 《邢台职业技术学院学报》2004,21(1):21-22,26
在进行平面凸轮廓形曲线数控编程前，必须首先选择一个数学方程来描述所处理的曲线。本文提出了一种新的凸轮廓形拟合方法，为后续的编程工作奠定了基础。 相似文献
9.
给出一种利用残差二次作图来修正作图法拟合线性方程的方法,利用该方法,可以使作图法拟合的线性方程更接近于用最小二乘法拟合的方程,从而减小作图法求直线截距和斜率的不确定度. 相似文献
10.
最小二乘法的拟合及其应用 总被引：1，自引：0，他引：1
邓亮章 《兰州教育学院学报》2012,(8):109-110,131
最小二乘法在很多领域都有着重要的应用。本文探讨了最小二乘法的一元线性拟合和多元线性拟合,并讨论了最小二乘法在经济预测中的应用。 相似文献
11.
Model fit indices are being increasingly recommended and used to select the number of factors in an exploratory factor analysis. Growing evidence suggests that the recommended cutoff values for common model fit indices are not appropriate for use in an exploratory factor analysis context. A particularly prominent problem in scale evaluation is the ubiquity of correlated residuals and imperfect model specification. Our research focuses on a scale evaluation context and the performance of four standard model fit indices: root mean square error of approximate (RMSEA), standardized root mean square residual (SRMR), comparative fit index (CFI), and Tucker–Lewis index (TLI), and two equivalence test-based model fit indices: RMSEAt and CFIt. We use Monte Carlo simulation to generate and analyze data based on a substantive example using the positive and negative affective schedule (N = 1,000). We systematically vary the number and magnitude of correlated residuals as well as nonspecific misspecification, to evaluate the impact on model fit indices in fitting a two-factor exploratory factor analysis. Our results show that all fit indices, except SRMR, are overly sensitive to correlated residuals and nonspecific error, resulting in solutions that are overfactored. SRMR performed well, consistently selecting the correct number of factors; however, previous research suggests it does not perform well with categorical data. In general, we do not recommend using model fit indices to select number of factors in a scale evaluation framework. 相似文献
12.
Alberto Maydeu-Olivares Amanda J. Fairchild Alexander G. Hall 《Structural equation modeling》2017,24(4):495-505
The power of the chi-square test statistic used in structural equation modeling decreases as the absolute value of excess kurtosis of the observed data increases. Excess kurtosis is more likely the smaller the number of item response categories. As a result, fit is likely to improve as the number of item response categories decreases, regardless of the true underlying factor structure or χ2-based fit index used to examine model fit. Equivalently, given a target value of approximate fit (e.g., root mean square error of approximation ≤ .05) a model with more factors is needed to reach it as the number of categories increases. This is true regardless of whether the data are treated as continuous (common factor analysis) or as discrete (ordinal factor analysis). We recommend using a large number of response alternatives (≥ 5) to increase the power to detect incorrect substantive models. 相似文献
13.
Linear factor analysis (FA) models can be reliably tested using test statistics based on residual covariances. We show that the same statistics can be used to reliably test the fit of item response theory (IRT) models for ordinal data (under some conditions). Hence, the fit of an FA model and of an IRT model to the same data set can now be compared. When applied to a binary data set, our experience suggests that IRT and FA models yield similar fits. However, when the data are polytomous ordinal, IRT models yield a better fit because they involve a higher number of parameters. But when fit is assessed using the root mean square error of approximation (RMSEA), similar fits are obtained again. We explain why. These test statistics have little power to distinguish between FA and IRT models; they are unable to detect that linear FA is misspecified when applied to ordinal data generated under an IRT model. 相似文献
14.
柴学宝 《天津职业院校联合学报》2009,11(2)
正弦规作为一种精密的量具,在测量零件角度、圆锥锥角方面发挥着非常好的功能。拓展正弦规的使用范围,使用正弦规测量燕尾配合角度的方法及原理,进一步阐述了其测量方法精度高,同时避免了传统测量方法中使用量具数量多,操作繁杂,效率低等不足。 相似文献
15.
在求解Packing问题、机器人路径规划、虚拟装配、三维圆形管道作任意斜切割、医疗内外科手术等经常用到椭圆一矩形的干涉算法,本文基于Adamowicz ＆ Albano的NFP概念,提出了椭圆一矩形的静、动态不适合边界（No Fu Boundary,NFB）和计算方法． 相似文献
16.
毕业生职业发展反映了高等教育的职业价值,是衡量高等教育质量的重要依据。基于人与环境匹配理论,评价高校毕业生职业发展质量应从关注外显性指标向人职匹配转变,分析毕业生与职业环境的互动及其对职业发展的影响。具言之,从需求-供给匹配维度评价毕业生职业期望的实现程度,从要求-能力匹配维度评价毕业生对任职要求的回应程度,从一致性匹配维度评价毕业生与工作集体的融洽程度。构建体现人与环境匹配理念的职业发展评价体系,提升在校生职业环境适应性,是发展以服务需求为导向高等教育的重要举措。 相似文献
17.
Stefanie A. Wind 《Educational Measurement》2020,39(4):76-94
Researchers have documented the impact of rater effects, or raters’ tendencies to give different ratings than would be expected given examinee achievement levels, in performance assessments. However, the degree to which rater effects influence person fit, or the reasonableness of test-takers’ achievement estimates given their response patterns, has not been investigated. In rater-mediated assessments, person fit reflects the reasonableness of rater judgments of individual test-takers’ achievement over components of the assessment. This study illustrates an approach to visualizing and evaluating person fit in assessments that involve rater judgment using rater-mediated person response functions (rm-PRFs). The rm-PRF approach allows analysts to consider the impact of rater effects on person fit in order to identify individual test-takers for whom the assessment results may not have a straightforward interpretation. A simulation study is used to evaluate the impact of rater effects on person fit. Results indicate that rater effects can compromise the interpretation and use of performance assessment results for individual test-takers. Recommendations are presented that call researchers and practitioners to supplement routine psychometric analyses for performance assessments (e.g., rater reliability checks) with rm-PRFs to identify students whose ratings may have compromised interpretations as a result of rater effects, person misfit, or both. 相似文献
18.
Sonya K. Sterba 《Structural equation modeling》2013,20(4):554-577
This article relates a still-popular motivation for using parceling to an unrecognized cost. The still-popular motivation is improvement in fit with respect to the item-solution. The cost is uncertainty in fit due to the selection of one out of many possible item-to-parcel allocations. A theoretical framework establishes the reason for this relationship: The same mechanisms that cause larger item- versus parcel-solution differences in the minimized discrepancy function also cause larger allocation to allocation variability in the parcel-solution's minimized discrepancy function. Study 1 illustrates that these shared causal mechanisms lead to a strong positive association between average item–parcel differences in minimized discrepancy function values and parcel-allocation variability in those values. Study 2 extends these results from discrepancy function values to fit indexes, showing that the association remains positive, but varies in magnitude depending on what quantities other than the discrepancy function are involved in computing the fit index. The important implication for practice is that when item–parcel fit differences are large enough to alter conclusions about model adequacy, parcel-allocation variability tends to be large enough for parcel-solution model adequacy to depend on the particular allocation chosen. 相似文献
19.
Fit indexes are an important tool in the evaluation of model fit in structural equation modeling (SEM). Currently, the newest confidence interval (CI) for fit indexes proposed by Zhang and Savalei (2016) is based on the quantiles of a bootstrap sampling distribution at a single level of misspecification. This method, despite a great improvement over naive and model-based bootstrap methods, still suffers from unsatisfactory coverage. In this work, we propose a new method of constructing bootstrap CIs for various fit indexes. This method directly inverts a bootstrap test and produces a CI that involves levels of misspecification that would not be rejected in a bootstrap test. Similar in rationale to a parametric CI of root mean square error of approximation (RMSEA) based on a noncentral χ2 distribution and a profile-likelihood CI of model parameters, this approach is shown to have better performance than the approach of Zhang and Savalei (2016), with more accurate coverage and more efficient widths. 相似文献
20.
大学生思想政治教育工作同大学生就业工作一样,都是高校中的重要工作。本文通过对大学生思想政治教育工作与就业工作契合的必要性和可能性以及方式进行全面细致的分析。本文研究的目的,在于培养符合社会需要的人才,促进学校事业健康有序发展。 相似文献